将集合附加到另一个集合

Is there a better way of appending a set to another set than iterating through each element ?

我有:

set<string> foo ;
set<string> bar ;

.....

for (set<string>::const_iterator p = foo.begin( );p != foo.end( ); ++p)
    bar.insert(*p);

有没有更有效的方法来做到这一点?

bar.insert(foo.begin(), foo.end());